What is a graph of isolated points

A graph of isolated points is a node of 0 degree. It is a point that doesn’t belong to any edge of the graph. The graph which is composed of isolated points is called discrete graph. Discrete graphs have discrete functions. They are scatter plot, a series of points which are not connected. They have no line nor a curve connecting them, only isolated points. They only consist certain numbers and the sets of data are said to be discrete if the values to the set are separate and distinct.